Sökning: "Hydrobiology"

Visar resultat 6 - 10 av 37 avhandlingar innehållade ordet Hydrobiology.

1. 6. The importance of terrestrial carbon in plankton food webs

   Författare :Cesar Bolivar Daniel; Biologiska institutionen; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Ecology; lakes; carbon; zooplankton; Spumella elongata; Poterioochromonas malhamensis; flagellates; bacteria; stable isotopes; photochemistry; autochthonous; DOC; allochthonous; plankton; Ekologi; Hydrobiology; marine biology; aquatic ecology; limnology; Marinbiologi; limnologi; akvatisk ekologi;

   Sammanfattning : Allochthonous substances, i.e. produced in terrestrial ecosystems, are known to fuel bacterial production in humic lakes. I observed that allochthonous carbon subsidizes bacteria even at high levels of phytoplankton biomass. LÄS MER

3. 7. Nitrogen transformations in wetlands: Effects of water flow patterns

   Författare :Torbjörn Davidsson; Biologiska institutionen; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Hydrobiology; hydrology; infiltration; subsurface flow; surface flow; wetland; nitrogen; Denitrification; mineralization; nitrification; marine biology; aquatic ecology; limnology; Marinbiologi; limnologi; akvatisk ekologi;

   Sammanfattning : In this thesis, I have studied nitrogen turnover processes in watermeadows. A watermeadow is a wetland where water infiltrates through the soil of a grassland field. LÄS MER

4. 8. Solar radiation effects on decomposition and decomposers of plant litter in lakes

   Författare :Måns Denward; Biologiska institutionen; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; glucosidase; photo inhibition; photo oxidation; littoral; lakes; ergosterol; fungi; phragmites; bacteria; UV-B; Hydrobiology; marine biology; aquatic ecology; limnology; Marinbiologi; limnologi; akvatisk ekologi;

   Sammanfattning : This thesis summarizes the results of a series of experiments, from test tube up to field study scale, performed to increase the understanding of solar radiation effects on decomposition and microbial decomposers of plant litter in stagnant water of littoral zones. In conclusion, I suggest that fungi play a significant role in the decomposition of plant litter submersed in lakes, and that their distribution is dependent on detritus quality and water chemistry, but also tends to be inversely related to the occurrence of bacteria attached to the litter. LÄS MER

5. 9. Regulation and role of epiphytic nitrification and denitrification in macrophyte-dominated systems

   Författare :Peder Eriksson; Biologiska institutionen; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; marine biology; Hydrobiology; submerged; emergent; epiphyton; bacteria; nitrate; wetland; nitrogen; littoral; aquatic ecology; limnology; Marinbiologi; limnologi; akvatisk ekologi;

   Sammanfattning : This thesis examines mechanisms regulating bacterial nitrification and denitrification in attached microbial communities on surfaces of aquatic macrophytes. It also evaluates the role of epiphytic nitrification and denitrification for the nitrogen turnover in macrophyte-dominated nutrient-rich freshwaters. LÄS MER

7. 10. Role of Lipids in the fate of organochlorine compounds in Aquatic Ecosystems

   Författare :Göran Ewald; LUCSUS; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Hydrobiology; biotransport; redistribution; bioaccumulation; extraction; ecological persistence; chlorinated fatty acids; DDT; PCB; organic pollutants; Lipids; triacylglycerols; phospholipids; marine biology; aquatic ecology; limnology; Marinbiologi; limnologi; akvatisk ekologi;

   Sammanfattning : Both results of laboratory experiments and material collected in the field have shown the lipid composition in organisms to have a significant effect on the bioaccumulation of pollutants and on the lipid steady-state concentrations of pollutants there. The redistribution of persistent organic pollutants which occurs in organisms as a consequence of the depletion of lipid depot, was studied in a population of migrating Pacific salmon (Oncorhynchus nerka). LÄS MER